Public officials can't escape the reach of the Freedom of Information Act by using private e-mail accounts for messages they would rather keep secret.
That's the clear implication of new guidance issued today by the Information Commissioner, Chris Graham, who says the law has been "somewhat misunderstood" in the past.
His statement may irritate some of those who already find FOI a source of aggravation, but I think it is unlikely however to result in much additional disclosure, since information could still be held back for other reasons.
The commissioner's intervention stems from the fuss in September over revelations in the Financial Times about the use of private e-mail by the Education Secretary Michael Gove and his advisers. The Department for Education denied this was an attempt to pre-empt the possibility of FOI requests.
But it was followed by stories about civil servants using text messaging with the aim of evading FOI, and reports of "panic" in Whitehall at the prospect of such tactics being stopped.
Mr Graham's verdict today is not remotely surprising. Information is covered by FOI if it is held by the public authority or by someone else on behalf of the authority - although it's not covered if held on behalf of another person.
Tablets of stone
So messages for purposes of official business are covered, even if sent via someone's personal Hotmail. But material that is truly personal or purely party political rather than the business of the authority is excluded, whether or not processed through the official email system.
In other words the mode of communication makes no difference. It doesn't matter whether your words are scribbled on removable sticky notes or chiselled into tablets of stone; it's equally irrelevant whether your thoughts are conveyed by text message or carrier pigeon.
The law seems pretty clear, as indeed was pointed out by various FOI specialists at the time of the Gove row. Yet the Education Department has claimed there was contrary guidance from the Cabinet Office, according to the Financial Times. However, this advice is apparently "not written down".
The BBC has made an FOI application to the Cabinet Office for any relevant guidance it has issued, but over two months later this has still not been answered.
Doubtless all this will now result in numerous FOI requests for the texts and Gmail messages of ministers and officials. But don't expect to be reading them soon.
The ICO advice simply confirms that they are subject to FOI in principle. Yet, just like any other document, they could still come under one of the exemptions in the FOI Act, such as policy formulation or the free and frank exchange of views.
So public authorities could refuse to release them if they reckon disclosure would be against the public interest. I think it is safe to predict that this is what public authorities will generally decide.
They could be overruled on appeal to the ICO, but I also expect that in practice the commissioner may demand a high threshold for the public interest before ordering disclosure, given the likely nature of most of the material and the commissioner's precedents on preserving a "private space" for discussions.
So the ominous forecasts of "fear" in Whitehall over "everything" being disclosable are hardly justified.
This issue has arisen in other countries, such as the US where some states have particularly far-reaching FOI regulations.
Many of Sarah Palin's private emails may have been published (she used her Yahoo account for Alaska state business). And there have also been a number of court cases resulting in text messages being released, such as a notorious collection of exchanges between the former Mayor of Detroit and his chief of staff.
In the UK now there remains the important question how thorough public authorities will be in checking private email accounts and text messages in response to FOI applications.
As one FOI officer argues, it will come down to "conscience and professionalism". He says "in practice, whether you provide emails to answer an FOI is still, largely, a matter of conscience". We may see how much people's consciences are tested in the light of the new guidance.
The ICO is clearly aware of the possibility of abuse. I was very interested to see that Mr Graham is now recommending that where private email is used for public authority business, "an authority email address must be copied in to ensure the completeness of the authority's records".
Now if public authorities really do ensure their staff comply with that, it will surely have an impact on what is put in some of those emails.
And not only in government departments like the Department for Education. I am aware for example of academics who use personal email for university business, as much to seek to escape the Data Protection Act (under which individuals can apply for the personal information held about them) as FOI.
So don't expect much more information to be released publicly as a result of Mr Graham's clarification of the law. But the dislike which some public sector staff feel towards the inconvenient requirements of the Freedom of Information Act will surely increase.
Still, there's always waving flags to create semaphore signals. That would get round FOI, because there's no lasting record.